Thyroid Hormone helps the body convert food into energy and heat, regulates body temperature, and impacts many hormonal systems in the body. Thyroid hormone exists in two major forms:  Thyroxine (T4), an inactive form that is produced by the thyroid gland and converted to T3 in other areas of the body, and Triiodothyronine (T3), the active form. The role of thyroid hormone and consideration of its impact on multiple body systems is emerging as a critical component of balanced hormone replacement for men and women.

Symptoms of hypothyroidism (low levels of thyroid hormone) include fatigue, cold and heat intolerance, hypotension, fluid retention, dry skin and/or hair, constipation, headaches, low sexual desire, infertility, irregular menstrual periods, aching muscles and joints, depression, anxiety, slowed metabolism and decreased heart rate, memory impairment, enlarged tongue, deep voice, swollen neck, PMS, weight gain, hypoglycemia, and high cholesterol and triglycerides. Yet, more than half of all people with thyroid disease are unaware of their condition.

Although both T4 (thyroxine, an inactive form that is converted to T3 in other areas of the body) and T3 (triiodothyronine, the active form) are secreted by the normal thyroid gland, many hypothyroid patients are treated only with levothyroxine (synthetic T4). For example, T4 preparations are often ineffective for patients with Chronic Fatigue and Immuno-Deficiency Syndrome (CFIDS) and Fibromyalgia(FM). The combination of pituitary dysfunction, high reverse T3, and thyroid resistance, leads to inadequate thyroid effect in most, if not all CFIDS/FM patients.

A T4/T3 combination preparation or straight T3 (triiodothyronine) may be preferable to T4 alone. However, the only commercially available form of T3 is synthetic liothyronine sodium (Cytomel®) in an immediate release formulation which is rapidly absorbed, and may result in higher than normal T3 concentrations throughout the body causing serious side effects. Research indicates there is a need for sustained-release T3 preparations in order to avoid adverse effects. Ultimately, it is the expertise of the prescriber, use and interpretation of appropriate tests, dosing of the T3 or T4/T3 combinations, and the formulation of the medications that determines the success of treatment.

N Engl J Med 1999 Feb 11;340(6):424-9

Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism.
A randomized, double-blind, crossover study found inclusion of T3 in thyroid hormone replacement improved cognitive performance, mood, physical status, and neuropsychological function in hypothyroid patients. Two-thirds of patients preferred T4 plus T3, and tended to be less depressed than after treatment with T4 alone. Patients and their physicians may wish to consider the use of sustained-release T3 in the treatment of hypothyroidism, particularly when the response to levothyroxine (T4) has not been complete.

J Endocrinol Invest 2002 Feb;25(2):106-9
Levothyroxine therapy and serum free thyroxine and free triiodothyronine concentrations.

John M. Lee, M.D., an Australian physician, points out that any thyroid function problem should be examined in the larger context of adrenal fatigue, hormone imbalances such as estrogen dominance, nutritional deficiencies, liver dysfunction, and digestion and absorption problems. Many vitamins, minerals and amino acids are needed to convert T4 to T3, and to get T3 into the cells. Dr. Lee believes that conservatively, 40% of women in the U.S. have measurably low thyroid and as a result are suffering from fatigue, depression, cold hands and feet, dry skin and hair and many other symptoms associated with hypothyroidism (low thyroid). Dr. Lee has a unique approach to treating patients with low thyroid function and advocates using only T3 for thyroid hormone replacement, and because the use of commercially-available T3 (liothyronine) is associated with serious problems such as rapid heart rate, Dr. Lee uses a slow-release T3 and reports the therapy is successful.

Thyroid Hormone helps the body convert food into energy and heat, regulates body temperature, and impacts many hormonal systems in the body. Thyroid hormone exists in two major forms:  Thyroxine (T4), an inactive form that is produced by the thyroid gland and converted to T3 in other areas of the body, and Triiodothyronine (T3), the active form. The role of thyroid hormone and consideration of its impact on multiple body systems is emerging as a critical component of balanced hormone replacement for men and women.Symptoms of hypothyroidism (low levels of thyroid hormone) include fatigue, cold and heat intolerance, hypotension, fluid retention, dry skin and/or hair, constipation, headaches, low sexual desire, infertility, irregular menstrual periods, aching muscles and joints, depression, anxiety, slowed metabolism and decreased heart rate, memory impairment, enlarged tongue, deep voice, swollen neck, PMS, weight gain, hypoglycemia, and high cholesterol and triglycerides. Yet, more than half of all people with thyroid disease are unaware of their condition.Although both T4 (thyroxine, an inactive form that is converted to T3 in other areas of the body) and T3 (triiodothyronine, the active form) are secreted by the normal thyroid gland, many hypothyroid patients are treated only with levothyroxine (synthetic T4). For example, T4 preparations are often ineffective for patients with Chronic Fatigue and Immuno-Deficiency Syndrome (CFIDS) and Fibromyalgia(FM). The combination of pituitary dysfunction, high reverse T3, and thyroid resistance, leads to inadequate thyroid effect in most, if not all CFIDS/FM patients.

A T4/T3 combination preparation or straight T3 (triiodothyronine) may be preferable to T4 alone. However, the only commercially available form of T3 is synthetic liothyronine sodium (Cytomel®) in an immediate release formulation which is rapidly absorbed, and may result in higher than normal T3 concentrations throughout the body causing serious side effects. Research indicates there is a need for sustained-release T3 preparations in order to avoid adverse effects. Ultimately, it is the expertise of the prescriber, use and interpretation of appropriate tests, dosing of the T3 or T4/T3 combinations, and the formulation of the medications that determines the success of treatment.

N Engl J Med 1999 Feb 11;340(6):424-9

Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism.

A randomized, double-blind, crossover study found inclusion of T3 in thyroid hormone replacement improved cognitive performance, mood, physical status, and neuropsychological function in hypothyroid patients. Two-thirds of patients preferred T4 plus T3, and tended to be less depressed than after treatment with T4 alone. Patients and their physicians may wish to consider the use of sustained-release T3 in the treatment of hypothyroidism, particularly when the response to levothyroxine (T4) has not been complete.

J Endocrinol Invest 2002 Feb;25(2):106-9

Levothyroxine therapy and serum free thyroxine and free triiodothyronine concentrations.

John M. Lee, M.D., an Australian physician, points out that any thyroid function problem should be examined in the larger context of adrenal fatigue, hormone imbalances such as estrogen dominance, nutritional deficiencies, liver dysfunction, and digestion and absorption problems. Many vitamins, minerals and amino acids are needed to convert T4 to T3, and to get T3 into the cells. Dr. Lee believes that conservatively, 40% of women in the U.S. have measurably low thyroid and as a result are suffering from fatigue, depression, cold hands and feet, dry skin and hair and many other symptoms associated with hypothyroidism (low thyroid). Dr. Lee has a unique approach to treating patients with low thyroid function and advocates using only T3 for thyroid hormone replacement, and because the use of commercially-available T3 (liothyronine) is associated with serious problems such as rapid heart rate, Dr. Lee uses a slow-release T3 and reports the therapy is successful.

Hashimoto’s Disease

While hypothyroidism is a condition, Hashimoto's is a disease. Hypothyroidism is commonly caused by Hashimoto's disease, but not always. Sometimes known as Hashimoto's thyroiditis, autoimmune thyroiditis, or chronic lymphocytic thyroiditis, Hashimoto’s is an autoimmune disease where antibodies interact with proteins in the thyroid gland, causing a gradual degradation of the gland, and decreasing the gland’s production of thyroid hormones. Possible symptoms include those common in hypothyroidism and is usually diagnosed with a clinical examination demonstrating one or more of the following:

  • A goiter (enlargement of the thyroid)
  • A radioactive uptake scan showing diffuse uptake in an enlarged thyroid
  • An ultrasound revealing an enlarged thyroid
  • Fine needle aspiration (biopsy) of the thyroid showing lymphocytes and macrophages
  • High antibody levels against thyroid peroxidase (TPO) and thyroglobulin (TG) detected with a blood test

Periods of anxiety, diarrhea, insomnia, and/or weight loss may come and go or be followed by periods of constipation, depression, fatigue, and/or weight gain as Hashimoto’s causes fluctuations in thyroid performance.  Such cycling can be typical with Hashimoto’s but is not always evident

Often Hashimoto’s is caused by environmental triggers such as iodine, infection, pregnancy, or cytokine therapy, resulting in the generation of large numbers of T helper cells, cytotoxic lymphocytes, and autoantibody-producing B cells. Immune cells accumulate in the thyroid and lead to a prevalence of T helper mediated autoimmune responses and cytotoxic effects of T lymphocytes. All of this results in apoptosis (destruction) of thyrocytes, which is the ultimate cause of Hashimoto’s thyroiditis. How is Hypothyroidism treated?

Most often, hypothyroid patients are treated with levothyroxine (synthetic T4). However, some patients remain symptomatic, and T3 is sometimes required for optimal therapy. Both T3 and T4 are secreted by a healthy thyroid gland.  Unfortunately, the only commercially available T3 is a synthetic liothyronine sodium in an immediate release form which is absorbed rapidly and can lead to high systemic T3 concentrations in the body, resulting in undesirable side effects, such as heart palpitations. AgeVital can compound sustained-release T3 which could be an alternative when the administration of T4 alone has not proven sufficient to produce the desired results. Some studies have shown that the inclusion of T3 in thyroid hormone replacement therapy has improved cognitive performance, neuropsychological function, overall physical status, and has reduced depression when compared to therapy with T4 alone.

Contact us if you have any additional questions about thyroid disorders or treatments. We are more than willing to assist you in your quest for information, and would welcome the opportunity to become part of your health team.